The goal of this study is to examine the relation of neonatal brain injury (NBI), in conjunction with other sources of biological and social risk, to psychopathology in a cohort of low birth-weight (LBW) adolescents. The study cohort is unique in three respects: it was geographically defined, representing nearly all births less than or equal to 200g in a three county region over a three year period; all members were screened for NBI with neonatal cranial ultrasound (US); and data are available from earlier assessments on neurodevelopmental handicap (age 2, psychopathology (age 6), school performance (age 9) and the environment (ages 0, 2, 6 and 9). At the proposed follow-up, adolescent psychopathology will be assessed with a structured diagnostic interview and with dimensional measures of behavior. Also to be obtained is information on adolescent motor and cognitive functioning, school performance, family history of psychiatric disorder and family functioning. The adolescent follow-up, in conjunction with earlier assessments, will provide an unprecedented opportunity to examine the emergence and course of psychopathology following early central nervous system (CNS) injury. As detected by US, the two most common forms of NBI in LBW infants are germinal matrix/intraventricular hemorrhage and parenchymal lesions and/or ventricular enlargement. These are probably pathophysiologically distinct lesions. However, both types of PBI might be expected to increase risk for adolescent psychopathology because they reflect injury to subcortical structures in the late second and early third trimester of gestation, with possible consequence for cell migration, cortical organization and myelination and for maturation of subcortical structures such as the striatum. The specific aims of this proposal are: 1) to determine the relation of NBI to adolescent psychopathology; 2) To assess the role of family history of psychiatric disorder as a risk factor for NBI and adolescent psychopathology; 3) to evaluate alternative causal models of co-morbidity among psychiatric and other (e.g. cognitive and motor) outcomes of NBI and 4) to examine pathways from NBI to adolescent psychopathology. The possible psychiatric consequences of NBI in LBW children are important public health problems in their own right, and may also provide insights into developmental aspects of brain-behavior relationships that can inform prevention and treatment.